I finish the demo with a kind of death warrior(with deadly combo). Your game is realy cool but it seems too much casual for me. It means that non-bosses/elites encounters are not enough powerfull to take down at least 1 Hp to your hero. I don't like the market system (more you play, more you have gold and then you can buy other heroes and cards). I think it could be better if you may take what you want to the begining but it's my point of view. A run can be long so if you can't access to the main features in the early game, it can be annoying. A good point, there are a fair pack of possibilities to make some cool combos.  Moreover, there are true choices between each battle (loot= at least 5 cards/speels or weapons). To conclude, Art is nice, concept looks cool but even if you can improve the difficulty system with some modifers, IA will be too dumb to be hard. Good luck with your game ! 

Note : I put this in commentary section 10  minutes ago(now it's remove) but i think it's better if you are the only one that can read my negatives aspects highlight because i'm not sure to what i'm talking about since it's just a demo. Si it wouldn't be faire if i put this on commentary section.  Thanks you for doing your best with making that grat game ! Have a good day/night/life, all of you !